Substituted triazines

ABSTRACT

TRIAZINES OF THE FORMULA   (R3-S-N(-R2)-),(R-N(-R1)-),X-1,3,5-TRIAZINE   WHEREIN X IS HALOEN OR ALKYLTHIO, R IS HYDROGEN OR ALKYL, R1 AND R2 ARE INDIVIDUALLY ALKYL AND R3 IS ARYL OPTIONALLY SUBSTITUTED WITH HALOGEN ATOMS, ALKYL GROUPS OR ALKOXY GROUPS, ARE USEFUL AS HERBICIDES.

United States Patent Office 3817,742 Patented June 18, 1974 3,817,742 SUBSTITUTED TRIAZINES Melancthon S. Brown, deceased, late of Berkeley, Calif., by Gustave K. Kohn, special administrator, Berkeley, Calif., assignor to Chevron Research Company, San Francisco, Calif.

No Drawing. Original application May 12, 1971, Ser. No. 142,758, now Patent No. 3,743,643. Divided and this application Apr. 23, 1973, Ser. No. 353,863

Int. Cl. A0111 9/22 U.S. CI. 71-93 14 Claims ABSTRACT OF THE DISCLOSURE Triazines of the formula wherein X is halogen or alkylthio; R is hydrogen or alkyl; R and R are individually alkyl and R is aryl optionally substituted with halogen atoms, alkyl groups or alkoxy groups, are useful as herbicides.

This is a division of application Ser. No. 142,758, filed May 12, 1971, now Pat. No. 3,743,643.

BACKGROUND OF THE INVENTION Field The present invention is directed to 2,4,6-substituted- 1,3,5-triazines and their use as herbicides. More particularly, the present invention is directed to Z-(N-arylthio- N-alkylamino)-4-alkylamino-6-haloor -6-a1kylthio-l,3,5- triazines.

Prior art Triazines and derivatives thereof are known to have utility in a variety of areas such as fungicides and herbicides. U.S. Pats. 2,891,855, 2,090,419 and 2,907,763 disclose amino substituted triazines and their use as herbicides. U.S. Pats. Nos. 3,079,391 and 3,138,445 disclose perchloromethylmercaptoamino triazines and their use as herbicides.

DESCRIPTION OF THE INVENTION Compounds of the present invention may be represented by the formula wherein X is hydrogen of atomic number 9 to 35 (fluorine, chlorine or bromine) or alkylthio of 1 to 4 carbon atoms; R is hydrogen or alkyl of l to 4 carbon atoms; R is alkyl of 1 to 4 carbon atoms; R is alkyl of 1 to 4 carbon atoms and R is aryl of 6 to 12 carbon atoms substituted with to 2 halogen atoms of atomic number 9 to 35, alkyl groups of 1 to 4 carbon atoms or alkoxy groups of 1 to 4 carbon atoms (the total number of substituents is preferably 2). Preferably, R is pheuyl substituted with 0 to 2 halogens of atomic number 9 to 35, alkyl groups of 1 to 4 carbon atoms or alkoxy groups of 1 to 4 carbon atoms.

Preferably X is chlorine or methylthio; R is hydrogen; R is alkyl of 1 to 3 carbon atoms; R is alkyl of 1 to 3 carbon atoms and R is phenyl substituted with 0 to 1 halogens of atomic number 9 to 35, particularly chlorine. More preferably R and R are the same.

Representative alkylthio groups which X may represent include methylthio, ethylthio, isopropylthio, npropylthio, n-butylthio, sec.butylthio, etc.

Representative alkyl groups which R, R and R may represent include methyl, ethyl, n-propyl, isopropyl, nbutyl, t-butyl, sec.butyl, etc.

Representative aryl groups which R may represent include phenyl, naphthyl, 4-chlorophenyl, '4-bromophenyl, 4-fluorophenyl, '3,4-dichlorophenyl, 2,4-dichlor0phenyl, 3,5-difluorophenyl, 4-methylphenyl, 4 ethylphenyl, 2- chloro-4-methylphenyl, 4-rnethoxypheuyl, 4-butoxyphenyl, 2,4-dimethoxyphenyl, etc.

Representative compounds of the present invention include 2- (N-phenylthio-N-methylamino) -4-me thylamino- 6- chloro- 1,3 5 -triazine,

2- N-phenylthio-N-methylamino) -4-dimethylamino- 6- fluoro-l,3 ,5-triazine,

2- N-4-chlorophenylthio-N-ethylamino) -4-methylamino- 6-chloro-1,3 ,5 -triazine,

2- N-4-chlorophenylthio-Nethylamino) -4-methylamino- 6-bromo-1,3 ,5-triazine,

2- N-'4-chlorophenylthio-N-ethylamino) -4-methylamino- 6 fluoro-1,3 ,5 -triazine,

2- N-4- clorophenylthio-N-ethylamino) -4-isopropylamino-6-chloro-1,3,5-triazine,

2- (N-3 ,4-dichlorophenylthio-N-methylamino) -4-methylethylamino-6-chloro-1,3, 5 -triazine,

2- (N-4-methylphenylthio-N-n-butylamino) -4-dimethylamino-6-methylthio-1, 3 5 -triazine,

2- N-4-methoxyphenylthio-N-isopropylamino) -4-t-b11tylamino-6-chloro-l,3,5-triazine,

2- N-2-chloro-4-methylphenylthio-N-ethylamino -4- methylisopropylamino-G-n-butylthio-1,3 ,5 -triazine,

2- (N-1-naphthylthio-N-methylamino) -4-methylamino- 6-chloro-l ,3,5-triazine, etc.

The compounds of the present invention are prepared by reacting a sulfeny lhalide with an aminotriazine in approximately equimolar amounts in the presence of a basic acceptor according to the following reaction wherein X, R, R R and R are as defined above and B represents a basic acceptor such as pyridine or triethylamine. The amount of basic acceptor should be at least equal in moles to the sulfenyl chloride. Normally the reaction is conducted in a polar water-miscible solvent such as dimethylformamide, acetonitrile, dimethoxyethane or dimethyl sulfoxide. In such highly polar solvents temperatures of 20 to 30 C. and reaction times of A to 10 hours are adequate for completion of the reaction. The product is isolated by adding a solvent not miscible with water, for example chlorinated hydrocarbons such as methylene chloride or chloroform, benzene, toluene, diethylether, etc. and then water washing to remove the initial solvent and the amine salt. The product can then be isolated further by addition of a noupolar solvent such as hexane or by evaporation to dryness. The crude product can be purified by recrystallization or chromatography.

When the aminotriazine reactant has R as H, and R and R as different alkyl groups, a mixture of products is obtained. Separation is generally accomplished by crystallization or chromatography.

Alternately, the compounds of the present invention can be prepared by conducting the reaction indicated above in the presence of a less polar solvent such as benzene or toluene in the presence of a tertiary amine such as 2,6- lutidine, collidine, pyridine or triethylamine. When using these solvents, such as benzene or toluene, higher reaction temperatures and longer reaction times will generally be desirable. A temperature of 50 C. up to the boiling point of the solvent will generally be employed. When the reaction is complete, the amine salt and the unreacted triazine may be removed by filtration and any residual amine salt washed outwith water. The product may then be isolated by evaporating to dryness or concentrating and precipitating with a less polar solvent such as hexane. The product may be purified by recrystallization or by digesting in a nonpolar solvent such as hexane.

The present invention can be more fully understood by reference to the following examples showing the preparation of select compounds. The examples are not considered limiting but are illustrative of the method of preparation. Unless otherwise indicated, percentages are by weight.

Example 1 .2- N-4-chlorophenylthio-N-ethylamino 4-ethylamino-6-chloro-1,3,5-triazine 14.2 g. (0.08 mole) of 4-chlorophenylsulfeny1 chloride was slowly added to 20.0 g. (0.1 mole) of 2,4-bis-cthylamino-6-chloro-1,3,5-triazine and 7.0 g. of pyridine in 100 ml. dimethylformamide at ambient temperature. The reaction mixture was stirred for two hours, diluted with 750 m1. diethyl ether, washed once with 500 ml. water twice with 250 ml. portions of water, followed by drying over magnesium sulfate and filtering. The solvent was removed under vacuum and the crude crystalline product purified by chromatographing on a silica gel column, eluting with ether-hexane. The product isolated by chromatography was further purified by recrystallizing from benzene-hexane. The recrystallized material melted at 131- 5 C. and analyzed as follows:

Calculated Found S, percent 9. 30 9.32 Cl, percent 20. 6 20. 70

Example 2.2- N-4-chlorophenylthio-N-isoproplamino) 4-isopropylamino-6-methylthio-1,3,5-triazine Calculated Found 8, percent 16. 71 16. 32 Cl, percent 9. 26 9. 84

4 Other compounds of the present invention were prepared and are tabulated in Table I.

The triazines of the present invention are, in general, herbicidal in both preand post-emergence applications. For pro-emergence control of undesirable vegetation these triazines will be applied in herbicidal quantities to the environment, e.g., soil infested with seeds and/ or seedlings of such vegetation. Such application will inhibit the growth of or kill the seeds, germinating seeds and seedlings. For post-emergence applications the triazines of the present invention will be applied directly to the foliage and other plant parts. Generally they are effective against weed grasses as well as broadleaved weeds. Some may be selective with respect to type of application and/or type of weed.

Preand post-emergence herbicidal tests on representative triazines of this invention were made using the following methods:

Pre-Emergence Test An acetone solution of the test triazines was prepared by mixing 750 mg. triazine, 220 mg. of a -nonionic surfactant and 25 ml. of acetone. This solution was added to approximately 125 ml. of water containing 156 mg. of surfactant.

Seeds of the test vegetation were planted in a pot of soil and the triazine solution was sprayed uniformly onto the soil surface at a dose of mg. per cm. The pot was watered and placed in a greenhouse. The pot was watered intermittently and was observed for seedling emergence, health of emerging seedlings, etc. for a 3-week period. At the end of this period the herbicidal effectiveness of the triazine was rated based on the physiological observations. A 0 to 100 scale was used; 0 representing no phytotoxicity, 100 representing complete kill.

Post-Emergence Test The test triazine was formulated in the same manner as described above for the pre-emergence test. The concentration of the triazine in this formulation was 5000 p.p.m. This formulation was uniformly sprayed on 2 replicate pots of 24-day-old plants (approximately 15 to 25 plants per pot) at a dose of 100 mg. per cm.. After the plants had dried, they were placed in a greenhouse and then watered intermittently at their bases as needed. The plants were observed periodically for phytotoxic effects and physiological and morphological responses to the treatment. After 3 weeks the herbicidal effectiveness of the triazine was rated based on these observations. A 0 to 100 scale was used; 0 representing no phytotoxicity, 100 representing complete kill. 1

The results of these tests appear in Table II.

TABLE II Herbicldal efieetiveness, pre/post Compound W C M P L 2-(N-4-chlorophenylthio-N-ethylanfino) +ethylamino'fi-chloro-l,3,5-triazine 99/100 98/100 98/100 98/100 100/100 100/10" 2- (N-4-chlorophenylthio-N-isopropylamino) -4-isopropylaminoG-methylthio- 1,3,5-tnazine- 75/100 100/100 100/100 100/100 100/100 100/100 2-(N-phenylthio-N-ethylamlno) -4-ethy1amino-6chloro-l,3,5-t!'iazine 100/100 100/100 100/100 100/100 100/100 100/100 2-(N4-9111orophenylthio-Nethylarnino)-4-isopropylamino16-chloro-1,3,5-

trlazme 100/100 100/100 100/100 100/100 100/100 100/100 Nora-O =Wild oats (Arena fat'lm). W=Watergrass (Echinochloa arvensis). P =Pigweed (Amaranthus retroflezus) L= Lambsquarter crusgalli). C Crabgrass (Digitaria sanguinalz's) M= Mustard (Brassica (Ohenopodium album).

The amount of triazine administered will vary with the particular plant part or plant growth medium which is to be contacted, the general location of application, i.e., sheltered areas such as greenhouses as compared to exposed areas such as fields, as well as the desired type of control. For pre-emergent control of most plants dosages in the range of about 0.5 to 20 lbs. per acre will be used. Such administration will give a concentration of about 2 to 80 p.p.m. triazine distribution throughout 0.1 acre-foot. For post-emergence application, such as foliar spray application, compositions containing about 0.5 to 8 lbs. triazine per 100 gal. spray will be used. Such application is equivalent to about 0.5 to 20 lbs. triazine per'acre.

The herbicidal compositions of this invention comprise a herbicidal amount of one or more of the above described triazines intimately admixed with a biologically inert carrier. The carrier may be a liquid diluent such as water or acetone or a solid. The solid may be in the form of dust powder or granules. These compositions will also usually contain adjuvants such as a Wetting or dispersing agent to facilitate their penetration into the plant growth media or plant tissue and generally enhance their eifectiveness. These compositions may also contain other pesticides, stabilizers, conditioners, fillers and the like.

As will be evident to those skilled in the art, various modifications on this invention can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

What is claimed is:

1. An herbicidal composition comprising an herbicidal quantity of a compound of the formula wherein X is halogen of atomic number 9 to 35 or alkylthio of 1 to 4 carbon atoms, R is hydrogen or alkyl of 1 to 4 carbon atoms; R and R are individually alkyl of 1 to 4 carbon atoms, R is carbocyclic aryl of 6 to 12 carbon atoms substituted with 0 to 2 halogen atoms of atomic number 9 to 35, with 0 to 2 alkyl groups of 1 to 4 carbon atoms or with 0 to 2 alkoxy groups of 1 to 4 carbon atoms; admixed with a biologically inert carrier therefor.

2. Composition of claim 1 wherein R is phenyl substituted with 0 to 2 halogen atoms of atomic number 9 to 35, with 0 to 2 alkyl groups of 1 to 4 carbon atoms, or with 0 to 2 alkoxy groups of 1 to 4 carbon atoms.

3. Composition of claim 2 wherein R is phenyl substituted with 0 to 1 halogen atom of atomic number 9 to 35.

4. Composition of claim 2 wherein R is hydrogen.

5. Composition of claim 1 wherein X is chlorine or methylthio; R is hydrogen; R is alkyl of 1 to 3 carbon atoms; R is alkyl of l to 3 carbon atoms and R is phenyl or chlorophenyl.

6. A method for controlling undesirable vegetation which comprises applying thereto an herbicidal amount of the compound of claim 1.

7. The method of claim 6 wherein R is phenyl substituted with 0 to 2 halogen atoms of atomic number 9 to 35, with 0 to 2 alkyl groups of 1 to 4 carbon atoms, or wtih 0 to 2 alkoxy groups of 1 to 4 carbon atoms.

8. The method of claim 7 wherein R is phenyl substituted with 0 to 1 halogen atom of atomic number 9 to 35.

9. The method of claim 7 wherein R is hydrogen.

10. The method of claim 6 wherein X is chlorine or methylthio; R is hydrogen; R is alkyl of 1 to 3 carbon atoms; R is alkyl of l to 3 carbon atoms and R is phenyl or chlorophenyl.

11. The method of claim 6 wherein the compound is 2-(N-4-chlorophenylthio-N-ethylamino) 4 ethylamino- 6-chloro-l,3,5-triazine.

12. The method of claim 6 wherein the compound is 2-(N-4-chlorophenylthio-N-isopropylamino) 4 isopropylamino-tS-methylthio-1,3,5-triazine.

13. The method of claim 6 wherein the compound is 2-(N-phenylthio-N-ethylamino 4 ethylamino-6-chloro- 1,3,5-triazine.

14. The method of claim 6 wherein the compound is 2 (N 4 chlorophenylthio-N-ethylamino)-4-isopropylamino-6-chloro-1,3,5-triazine.

References Cited UNITED STATES PATENTS 3,141,885 7/1964 Ross et a1. 260249.8

LEWIS GOTTS, Primary Examiner C. L. MILLS Assistant Examiner 

